Basement Conversions
London Specialists
Premium basement conversions — cinema rooms, gyms, wine cellars, guest suites.
Our Basement Conversion Services
Cinema Room
Soundproofed home cinema with projector and surround sound.
Home Gym
Impact-absorbing floors, mirrors, ventilation, rubber matting.
Wine Cellar
Climate-controlled wine storage with tasting area.
Guest Suite
Self-contained bedroom, bathroom, and kitchenette.
Home Office
Sound-insulated workspace with natural light wells.
Utility & Plant Room
Relocate services below ground to free up main floors.
What to Expect
Structural Engineering
Every basement requires a structural engineer. We work with experienced SE firms on every project.
Party Wall Act
If you share a wall with neighbours, Party Wall Agreements are legally required. We manage this process.
Planning Permission
Most basement conversions are permitted development, but we confirm this for every project.
Waterproofing
Grade 3 dry habitable space requires full tanking or cavity drain membrane system.
How It Works
Structural Survey
Ground investigation, party wall notices.
Engineering & Planning
Structural design, building regs, CDM plan.
Excavation & Structure
Underpinning, waterproofing, structural slab.
Fit-Out & Finish
M&E, finishes, and final handover.
Basement Conversion Cost Estimator
Estimates are indicative only. Final costs depend on site conditions, specification, and access. Get a free, no-obligation quote for an accurate price.
What Our Clients Say
“SuperBuilder underpinned and converted our entire basement into a cinema room, wine cellar, and gym. The structural engineering was complex but they managed it flawlessly. We gained 80m² of living space.”
Robert & Karen S.Notting Hill, W11 · Full Underpinning“Existing Victorian cellar converted into a stunning guest suite with en-suite shower room. The waterproofing is perfect — completely dry even after heavy rain. Excellent craftsmanship throughout.”
Charles W.Hampstead, NW3 · Cellar Conversion“Home office and treatment room in our new basement. The acoustic insulation is superb — no sound from the family above. Natural light wells make it feel spacious. The project was managed expertly.”
Dr Patel & Dr SinghRichmond, TW9 · Home Office
Frequently Asked Questions
Ready to Get Started?
Call us today for a free, no-obligation site survey and estimate.